So far, over 1,000 people have been evacuated from the low-lying areas of Kanyakumari and put into the relief camps. 22 people are said to be missing.
620 houses have been full damaged and around 240 are partly damaged. Kanniyakumari - Tirunelvelli highway has also been blocked due to tree fall.
Several areas are without electricity and schools have been shut for today.
Four people were killed and dozens of houses were damaged in rain-related incidents in Tamil Nadu's Kanyakumari, the police said.
Dozens of fishermen from Kerala remain missing and are suspected to be stranded at sea. Angry groups of fishermen in the coastal villages in Poovar, Vizhinjam , Kovalam have threatened to block the highway, if rescue operations were not intensified.
Vincent, a rescued fisherman, told news agency IANS, "It was a nightmare as massive waves were smashing all around and the boat that we were on, after holding on for an hour, lost balance and overturned."
Several trains to and from Kerala's capital of Thiruvananthapuram were either delayed, cancelled or re-scheduled due to heavy rains overnight and the forecast of further rains.
According to the latest weather bulletin, the meteorological office predicts heavy to very heavy rains at isolated places over the south Tamil Nadu and south Kerala.